Distributors of the above mentioned kind are known, e.g. from U.S. Pat. No. 5,269,372 wherein a cold plate for cooling electronic modules incorporates a flow network with supply and return conduits for a cooling fluid. In US application no. 2001/0050162, a plurality of plate elements are stacked to form a core with a heat-transfer surface which can be arranged towards a microprocessor device. In the above-mentioned disclosures, the fluid is guided in a device which is separate from the component to be cooled. Even though this independency allows a certain degree of freedom during a manufacturing and assembling process, it results in relatively high manufacturing and assembling costs and since the fluid is separated from the electronic component to be cooled, the cooling efficiency could be reduced.
In WO 03/095922 wherein a bottom side plate of a semi-conductor unit is cooled by a liquid which is guided along the plate in direct contact with the plate, the efficiency could be improved by the direct contact. The open structure of the cooling device, however, implies a demand for increased tolerances on the sealing surfaces of the distribution unit and the plate which is to be cooled, and moreover, direct contact between the electronic component and the cooling fluid may influence the reliability of the electronic component.
In U.S. Pat. No. 4,072,188 a fluid cooling system for electronic systems is disclosed wherein a heat exchanger with side walls and a back wall form a chamber, and wherein a flexible wall is fastened or bonded to the side walls to close the chamber. Because of the flexibility, the pressure of the circulating heat exchange medium in the chamber forces the flexible wall into contact with an adjacent substrate to be cooled. If the pressure of the circulating medium exceeds a certain limit, the flexible wall may deflect to an extent where the flexible wall deforms permanently, or the pressure of the flexible wall against the substrate may overload and possibly destroy the substrate. To overcome this problem, one solution would be to reduce the pressure of the circulating medium. This, however, may change the flow conditions and the amount of the fluid which is circulated in the system and thereby reduce the thermal conductivity and heat exchange. Another solution could be to increase the wall thickness or stiffness of the flexible wall. This, however, would influence the thermal conductivity between the medium and the substrate through the flexible wall.